Officials said arrests for drug use and illicit sex at the beach on the Wisconsin River just north of Mazomanie spiked last year. In just nine days of surveillance, wardens arrested 42 people for illicit sex or drug possession, up from 14 in six days in 2007.

To try to curb the behavior, the state Department of Natural Resources said Tuesday it will close down huge expanses of the woods around Mazomanie Beach in hopes of forcing people into clear view.

The DNR put new signs up announcing what areas will be closed to the public on Monday. DNR officials will continue to allow access to the beach, but limit the public's access to the forest surrounding it. The closures will be in place from now until Sept. 15, they said.

"The goal of the additional closures is to reduce user conflicts and to make this a safe and enjoyable environment for everyone who visits the riverway," said conservation warden Jeremy Plautz.

Wardens said they have run into illicit sexual activity on the property off and on for decades. Some national websites have brought unwanted publicity to the beach, which has led people as far away as Florida to come to the beach looking for a sexual encounter, according to the DNR.

Nudists aren't happy with the plan, but other river users say something must be done.

The beach itself, along with an access road to it, will remain open from 6 a.m. to 8 p.m. every day throughout the summer.

Copyright 2012 by Channel 3000. The Associated Press contributed to this report. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.